A prior art pushing device for pushing forward a line of blister-packaged articles by using spring force of reversed U-formed leaf-spring is disclosed in Japanese Utility Model Publication (JIKKOU SHOU) No. 60-18123. This pushing device is designed for pushing forward blister-packaged article suspended in line but involves the following disadvantages: This device has only one bending point and, therefore, may be overloaded thereat, loosing self-restoring force. In addition, the device is so large not to be easily used.
To solve the above-mentioned problem involved in the prior art device, the present applicant previously proposed, in Japanese patent application No. 7-145197 (hereinafter referred to as the previous application), a compact elastic type pushing device capable of working with a reduced load on its bent portions, which is an elastically bent (zigzag) type compression spring plate that is removably fitted on a hook bar to push forward a queue of articles slidably hanging from the hook bar by transmitting self-restoring force thereto through its front pushing end.
The hanging article pushing device of the previous application, however, has following problems:
(1) There are two differently formed pushing devices which are used on a single hook bar and a double hook bar respectively and can not be commonly used. PA0 (2) The pushing device can be compressed with the zigzagged spring plate not to be tightly contracted (causing needless air gaps) and, therefore, can not satisfy users' desire to hang more quantity of articles on the hook bar. PA0 (3) The pushing device can not be fitted on the hook bar without previously removing articles therefrom. PA0 (4) The pushing end of the pushing device may be deformed resulting in insufficient movements of articles along the hook bar. PA0 (1) An object of the present invention is to provide an article pushing device comprising a zigzag leaf-spring, which has a series of notches in the axial direction of acting its self-restoring force and is slidably fitted at its notches onto an axis to be set (e.g., a hook bar) for applying a pushing force to a line of articles hanging from the hook bar by transmitting thereto an elastic self-restoring force through its one end. PA0 (2) Another object of the present invention is to provide an article pushing device as mentioned above in item (1), which is characterized in that it has at least one series of the notches cut in the upper bent portions for fitting onto an axis to be set (e.g., hook bar) without impairing the function of the leaf-spring. PA0 (3) Another object of the present invention is to provide an article pushing device as mentioned above in item (1) or (2), which is characterized in that the upper bent portions have notches each of which has a two-stepped form consisting of an open-slit and a sliding-hole and can be easily fitted through the open-slit onto an axis to be set (e.g., a hook bar body). PA0 (4) Another object of the present invention is to provide an article pushing device as mentioned above in any one of items (1) to (3), which is characterized in that the zigzag leaf-spring can be compressed to its minimal length, aligning all zigzags almost tight and and parallel to each other and reserving the necessary self-restoring force for assuring a long stroke and maximal use of a space on an axis to be set. PA0 (5) Another object of the present invention is to provide an article pushing device as mentioned above in any one of items (1) to (4), which is characterized in that the zigzag leaf-spring is provided at least at its one end with a pushing portion having an acting point on an article and being capable of concentrating its self-restoring force to the acting point on the article, realizing effective pushing forward the article. PA0 (6) Another object of the present invention is to provide an article pushing device as mentioned above in any one of items (1) to (5), which is characterized in that the zigzag leaf-spring is provided with fixing means for stably fixing on an axis to be set (e.g., a hook bar), enabling the zigzag leaf-spring to generate its self-restoring force necessary for stably feeding the articles. PA0 (7) Another object of the present invention is to provide an article pushing device as mentioned above in any one of items (1) to (6), which is characterized in that the the fixing means having a fitting portion with an opening aligned coaxially to notches made in the upper bent portions is formed integrally with the zigzag leaf-spring in order to easily fix the zigzag leaf-spring at any desired position on an axis to be set (e.g. , the hook bar).